The present invention relates to a press, multistation press or similar forming machine of this type.
The end areas of a press must perform the inserting of sheet bars and their removal after the shaping process. In this case, the drive of the transport rails for the transfer movement may be assigned to the removal area of the press. The removal may take place via a transport belt. The inserting takes place by a sheet bar loader which, as a result of its multiple tasks--separating of the sheet bars; cleaning and possibly aligning of these sheet bars; orienting and inserting of the sheet bars into a first station of the press may require a lot of space and expenditures in the inserting area of the press. In previous presses that use transport rails for transferring of the workpieces, the end sections of the transport rails extend, corresponding to the transfer lift, into the area of the sheet bar loader. As a result of the mutually advancing movement for the gripping of the workpieces and the transfer movement, a significant narrowing takes place with respect to the sheet bar loader.
U.S. Pat. Nos. 4,149,400; 4,540,087; and 4,630,461 show transport rails which extend into the area of the sheet bar loader and thus beyond the area of the initiating of the lifting/lowering movement and of the opening/closing movement. The presses shown in those patents all have solutions for the guiding of the transport rails, in which the length of the running rails caused by the length of the transfer movement is calculated into the moved part of the guide, thus into the transport rail. On the one hand, the transport rails must have a construction which is longer by this extent of the movement; on the other hand, there are the already mentioned space limitations for the sheet bar loader.
An object of the present invention is to overcome the above-mentioned problems so that the transport rails do not present a hindrance with respect to the sheet bar loader. Sheet bar loaders which have a different construction and therefore also corresponding dimensions may be used in the present invention.
This and other objects are achieved by the present invention which provides a press having a plurality of machining stations, comprising transport rails and holding devices on the transport rails. These transport rails provides a transfer movement of workpieces in the machining stations, the transport rails having guiding devices. First driving devices are coupled to the transport rails for applying the transfer movement in a first end area of the transport rails. Second driving devices are coupled to the transport rails for applying a lifting/lowering movement to the transport rails. Third driving devices are coupled to the transport rails for applying an opening/closing movement to the transport rails at the first end area and at a second end area of the transport rails. Guides are provided at the second end area of the transport rails on which the guiding devices of the transport rails run in a transfer movement direction. The guides have a length that is a function of the length of the transfer movement of the transport rails and of the length of the guiding devices.
Special advantages are obtained with the present invention because the actual guide rails or guide surfaces do not move along into the transfer device.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.